Method and system for umts hsdpa shared control channel processing

ABSTRACT

Aspects of a method and system for UMTS HSDPA Shared Control Channel processing may include calculating at a receiver, for each one of a plurality of control channels, a quality metric based at least one Viterbi Decoder state metric. A control channel may be selected on the basis of the quality metrics, where the quality metric is selected that provides maximum confidence. The selected control channel may be chosen if its corresponding 3GPP metric is greater than a specified threshold, where the threshold is a design parameter. A validity of a selected control channel may be determined based on consistency and a CRC, where the CRC may be derived from decoding a sub-frame. The calculating and selecting may be done for a first slot of a sub-frame for High-Speed Shared Control Channels.

CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE

None.

FIELD OF THE INVENTION

Certain embodiments of the invention relate to signal processing. Morespecifically, certain embodiments of the invention relate to a methodand system for UMTS HSDPA Shared Control Channel processing.

BACKGROUND OF THE INVENTION

Mobile communications has changed the way people communicate and mobilephones have been transformed from a luxury item to an essential part ofevery-day life. The use of mobile phones is today dictated by socialsituation, rather than by location or technology. While voiceconnections fulfill the basic need to communicate, and mobile voiceconnections continue to filter even further into the fabric of life, themobile Internet is the next step in the mobile communication revolution.The mobile Internet is poised to become a common source of information,and easy, versatile mobile access to this data will be taken forgranted.

Third generation (3G) cellular networks have been specifically designedto fulfill these future demands of the mobile Internet. As theseservices grow in popularity and usage, factors such as cost efficientoptimization of network capacity and quality of service (QoS) willbecome ever more essential to cellular operators. These factors may beachieved with careful network planning and operation, improvements intransmission methods, and advances in receiver techniques. To this end,carriers need technologies that will allow them to increase downlinkthroughput and, in turn, offer advanced QoS capabilities and speeds thatrival those delivered by cable modem and/or DSL service providers. Inthis regard, networks based on wideband CDMA (WCDMA) technology can makethe delivery of data to end users a more feasible option for today'swireless carriers.

WCDMA has evolved continuously towards higher data rates and towardspacket-switched IP-based services. The following paragraphs elaborate onthe evolution to HSDPA from GPRS via EDGE.

The GPRS and EDGE technologies may be utilized for enhancing the datathroughput of present second generation (2G) systems such as GSM. TheGSM technology may support data rates of up to 14.4 kilobits per second(Kbps), while the GPRS technology may support data rates of up to 115Kbps by allowing up to 8 data time slots per time division multipleaccess (TDMA) frame. The EDGE technology, a further enhancement to GPRS,may support data rates of up to 384 Kbps. The EDGE technology mayutilizes 8 phase shift keying (8-PSK) modulation to provide higher datarates than those that may be achieved by GPRS technology. The GPRS andEDGE technologies may be referred to as “2.50” technologies.

The UMTS technology with theoretical data rates as high as 2 Mbps, is a3G evolution of GSM, using wideband CDMA technology. UMTS may achievehigher data rates than GSM/EDGE due to many enhancements, includinghigher transmission bandwidth, adaptive higher order modulation andinterference averaging due to a unity frequency reuse factor.

The High-Speed Downlink Packet Access (HSDPA) technology is an Internetprotocol (IP) based service, oriented towards data communications, whichadapts WCDMA to support data transfer rates in the order of 14 megabitsper second (Mbit/s). Developed by the 3G Partnership Project (3GPP)group, the HSDPA technology achieves higher data rates through aplurality of methods. In order to avoid excessive interference, 2G WCDMAmay require fast power control to maintain a constant data rate. TheHSDPA technology changes this paradigm and instead maintains a constanttransmission power but may change the coding and modulation rate toadapt to changing channel conditions. Other methods that may be used toimprove the data throughput are fast packet scheduling and a fastretransmission of lost packets by using Hybrid Automatic Repeat Requesttechniques.

The HSDPA system may consist of a High-Speed Physical Downlink SharedChannel (HS-PDSCH/HS-DSCH), which permits a plurality of users to sharethe high-speed data connection. Additionally, a plurality of supportchannels may be available to carry control and setup information. Inparticular, a plurality of High-Speed Downlink Shared Control Channels(HS-SCCH) may be present. These control channels may carry signalinginformation for the User Equipment (UE, that is the mobile terminal) andmay contain information about when the UE may expect data and how thedata will be encoded.

Since processing of the HS-SCCH channel takes place at the UE, theseoperations may be very sensitive to power consumption. However, loweringthe quality of the signal processing in order to save energy, may leadto more significant power expenditure due to incorrect decisions taken.For example, this may be the case when the UE erroneously changes fromstand-by mode to HS-PDSCH receiver mode based on incorrectly decodedHS-SCCH data. It is therefore important to devise methods that may leadto a minimum of errors in the decoding of the HS-SCCH and that may use aminimum of power.

Further limitations and disadvantages of conventional and traditionalapproaches will become apparent to one of skill in the art, throughcomparison of such systems with some aspects of the present invention asset forth in the remainder of the present application with reference tothe drawings.

BRIEF SUMMARY OF THE INVENTION

A method and/or system for UMTS HSDPA Shared Control Channel processing,substantially as shown in and/or described in connection with at leastone of the figures, as set forth more completely in the claims.

These and other advantages, aspects and novel features of the presentinvention, as well as details of an illustrated embodiment thereof, willbe more fully understood from the following description and drawings.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1A illustrates an exemplary HSDPA distributed architecture thatachieves low delay link adaptation, in connection with an embodiment ofthe invention.

FIG. 1B is a diagram illustrating an exemplary HSDPA channel structure,which may be utilized in connection with an embodiment of the invention.

FIG. 2 is an exemplary diagram illustrating the frame structure and thetiming that may be used to elaborate on the interactions between theHS-SCCH control channel and the HS-PDSCH shared downlink data channel.

FIG. 3 is a diagram illustrating a HS-SCCH first slot receiver, inaccordance with an embodiment of the invention.

FIG. 4 shows an exemplary 8-state trellis diagram of an 8-stateconvolutional code Viterbi decoder, in connection with an embodiment ofthe invention.

FIG. 5 is a flow diagram illustrating exemplary steps for processingHigh-Speed Shared Control Channels, in accordance with an embodiment ofthe invention.

DETAILED DESCRIPTION OF THE INVENTION

Certain embodiments of the invention may be found in a method and systemfor UMTS HSDPA Shared Control Channel processing. Aspects of a methodand system may comprise calculating at a receiver, for each one of aplurality of control channels, a quality metric derived from at leastone Viterbi Decoder state metric. A control channel may be selected onthe basis of the quality metrics, where the quality metric is selectedthat provides maximum confidence. The selected control channel is chosenif its corresponding 3GPP metric is greater than a specified threshold,where the threshold is a design parameter. A validity of a selectedcontrol channel is determined based on consistency and a CRC, where theCRC may be derived from decoding a sub-frame. Calculating and selectingmay be done for a first slot of a sub-frame for High-Speed SharedControl Channels.

FIG. 1A illustrates an exemplary HSDPA distributed architecture thatachieves low delay link adaptation, in connection with an embodiment ofthe invention. Referring to FIG. 1A, there is shown user equipment (UE)110 and 112 and a base station (BS) 114. There is also shown a datapath, data, and a layer 1 feedback path, L1 feedback. The data path maybe used to transmit payload data such as Voice or IP-data from the BS tothe UE. The L1 feedback path may be used to feed back controlinformation such as latency or channel quality from the UE to the BS.

HSDPA is built on a distributed architecture that achieves low delaylink adaptation by placing key processing at the BS 114 and thus closerto the air interface than if the same processing would take place in thecore network. Accordingly, the MAC layer (Layer 2) at the BS 114 isclosely integrated with the Physical Layer (Layer 1), which implies thatthe systems may respond in a much faster manner with data access.

The HSDPA technology employs several important new technologicaladvances. Some of these may comprise scheduling for the downlink packetdata operation at the BS 114, higher order modulation, adaptivemodulation and coding, hybrid automatic repeat request (HARQ), physicallayer feedback of the instantaneous channel condition, and a newtransport channel type known as high-speed downlink shared channel(HS-DSCH) that allows several users to share the air interface channel.When deployed, HSDPA may co-exist on the same carrier as the currentWCDMA and UMTS services, allowing operators to introduce greatercapacity and higher data speeds into existing WCDMA networks. HSDPAreplaces the basic features of WCDMA, such as variable spreading factorand fast power control, with adaptive modulation and coding, extensivemulticode operation, and fast and spectrally efficient retransmissionstrategies. Thus, significant gains in average data throughput rates maybe obtained between the user equipment 110 and 112 and the base station114.

FIG. 1B is a diagram illustrating an exemplary HSDPA channel structure,which may be utilized in connection with an embodiment of the invention.Referring to FIG. 1B, there is shown a base station 116, a userequipment (UE) 118, a High-Speed Physical Downlink Shared Channel(HS-PDSCH) 120, a plurality of High-Speed Shared Control Channels(HS-SCCH) 120 and a High-Speed Dedicated Physical Control Channel(HS-DPCCH) 124. Referring to FIG. 1B, three additional channel types maybe used to support a HSDPA connection between the base station 116 andthe user equipment 118. A high-speed physical downlink shared channel(HS-PDSCH) 120 and a plurality of high-speed shared control channels(HS-SCCH) 122 may be used on the downlink between the base station 116and the UE 118. A high-speed dedicated physical control channel(HS-DPCCH) 124 may used on the uplink between the UE 118 and the basestation 116.

A plurality of UE 118 may share the data capacity of the HS-DSCH 120,where the data is separated both by spreading code and time slot. Inorder to support this function, the UE 118 may obtain controlinformation over the HS-SCCH 122. Decoding the HS-SCCH 122 may providethe UE 118 the fast changing parameters needed for reception of theHS-PDSCH 120. In the uplink direction, there may be a HS-DPCCH 124 forsending back data packet acknowledgments and channel quality informationthat may be used by the BS 116 to schedule the transmissions todifferent UEs 118.

Like the HS-PDSCH 120, a plurality of HS-SCCH 122 channels may be sharedamong a plurality of UEs, whereas the HS-DPCCH 124 may be dedicated to asingle UE 118. There may be up to four HS-SCCH 122 channels configuredfor a single UE 118, although only one may carry information from the BS116 intended for the UE 118 at any one time. Hence, up to 4 HS-SCCHchannels 122 may need to be monitored simultaneously at the UE 118.

FIG. 2 is an exemplary diagram illustrating the frame structure and thetiming that may be used to elaborate on the interactions between theHS-SCCH control channel and the HS-PDSCH shared downlink data channel.Referring to FIG. 2, there is shown a HS-SCCH frame 200, a HS-PDSCHframe 202 and the HS-SCCH sub-frame structure 204, The HS-SCCH frame 200comprising of 5 sub-frames, 206 ₀₋₄. The HS-PDSCH frame 202 may comprise5 sub-frames, of which 4 sub-frames, namely 206₀₋₃ are shown.

The structure of the HS-SCCH sub-frame 204 comprises the sub-frame 206,comprising a first timeslot 208 and a plurality of timeslots 210. TheH-SCCH frame 200 and the corresponding HS-PDSCH 202 overlap by 1timeslot, as illustrated in the first sub-frame of the HS-SCCH 206 ₀ andthe first sub-frame of the HS-PDSCH 212 ₀. The UE may receive theHS-PDSCH data channel sub-frame 212 ₀ before the end of the controlsub-frame 206 ₀ because the data necessary to setup receiving theHS-PDSCH sub-frame 212 ₀ may be contained in the first timeslot of theHS-SCCH sub-frame 206 ₀, which may comprise the UE identity, thespreading code set used and the modulation used, for example either QPSKor 16QAM. The HS-SCCH 206 sub-frame structure in 204 may comprise afirst timeslot 208 comprising the HS-PDSCH setup information, followedby two slots 210 comprising other information necessary to process theinformation obtained on the HS-PDSCH, such as transport block size orhybrid-ARQ information.

Since the recipient of every HS-PDSCH such as HD-PDSCH sub-frame 212 ₀₋₃may change every sub-frame, as may be signaled in the correspondingHS-SCCH sub-frames 206 ₀₋₃, the receiver of the HS-SCCH control channel200 may need to decode the first timeslot 208 of the HS-SCCH sub-frame206 ₀₋₃ and initiate the setup for receiving the corresponding HS-PDSCHsub-frame 212 ₀₋₃ during the second timeslot 210. To ensure that onlythe UE that is addressed may decode the setup information contained inthe HS-SCCH sub-frames, the data in the first timeslot 208 may be maskedwith a bit-string derived from the corresponding UE identity. In thismanner, only the addressed UE identity may correctly decode the firsttime slot of the HS-SCCH sub-frame containing the setup information forthe associated HS-PDSCH sub-frame.

FIG. 3 is a diagram illustrating a HS-SCCH first slot receiver, inaccordance with an embodiment of the invention. Referring to FIG. 3,there is shown Un-masking blocks 302, 312, 322, 332, Un-Puncturingblocks 304, 314, 324, 334, Viterbi Decoders 306, 316, 326, 336 andDecision block 340.

A plurality of up to four HS-SCCH control channels may be assigned to asingle UE, denoted by HS-SCCH0, HS-SCCH1, HS-SCCH2 and HS-SCCH3. Onlyone of the control channels, however, may carry information for aparticular UE at any time. It may hence be necessary to decode all fourcontrol channels simultaneously because the UE does not know whichcontrol channel may bear the information required to set up thedata-carrying HS-PDSCH channel. The processing chain may be identicalfor each HS-SCCH channel, that is, the blocks 302, 312, 322, 332 may beidentical, as well as 304, 314, 324, 334 and 306, 316, 326, 336. Thereceiver chain for HS-SCCH0, which comprises Un-Masking 302,Un-Puncturing 304 and Viterbi Decoding 306, may be utilized toillustrate operation of each of the receiver chain illustrated in FIG.3. The parallel receiver branches for HS-SCCH1, HS-SCCH2 and HS-SCCH3may be processed identically.

The Un-masking block 302 may comprise suitable logic, circuitry and/orcode that may be utilized to decode the first time slot of a sub-frameof HS-SCCH0, with reference to FIG. 2. In the absence of a matching UEmask in the first slot of a control signal HS-SCCH0, the decoded outputof the Un-masking block 302 may essentially be data without meaning.

In the Un-Puncturing block 304 may comprise suitable logic circuitryand/or code that may be utilized to re-insert into the data streamentering 304, a plurality of symbols that may have been removed in thepuncturing process at the transmitter. The values of these re-insertedsymbols may be zero or any other appropriate values.

The data resulting from the un-Puncturing process may be communicated tothe Viterbi decoder 306. The Viterbi decoder may comprise suitable logiccircuitry and/or code that may be utilized to decode theerror-correcting convolutional coding applied at the transmitter. TheViterbi decoder 306 may enable generation of a data word that may mostlikely have been transmitted. In addition, a quality metric indicating ameasure of confidence in the decoded data word may be calculated.

The decoded data words and their associated quality metric from theplurality of control channel Viterbi decoders, blocks 306, 316, 326 and336, respectively, may then be communicated to the Decision block 340.Based on the numerical value of the quality metric, the decision block340 may then decide which HS-SCCH branch most likely (with the maximummeasure of confidence) carries the information intended for the UE. Thedecoded data word associated with the quality metric indicating thehighest confidence may be switched through and signaled at the output ofthe Decision block 340 as the final data word.

It may also be the case that none of the plurality of HS-SCCH containsany information intended for a given UE in a given sub-frame. Todetermine whether a signal carrying meaningful data may be present, the3GPP metric associated with the Viterbi decoder corresponding to thedecoded data word associated with the quality metric indicating maximumconfidence, may be compared to a threshold value D in the Decision block340. If the 3GPP metric is greater than or equal to the threshold D, avalid signal may be assumed to have been decoded. If the 3GPP metric isinferior to the threshold D, the signal decoded is assumed to have beeninvalid. The threshold value D is a design-parameter.

FIG. 4 shows an exemplary 8-state trellis diagram of an 8-stateconvolutional code Viterbi decoder, in connection with an embodiment ofthe invention. Associated with a Viterbi decoder for an n-stateconvolutional code is a state metric for each of n possible states.After n soft input symbols entering the Viterbi decoder, n state metricswill be available for each of n states. The maximum metric may bedefined as:

${MaxMetric} = {\max\limits_{i = {\{{0,1,{\ldots \; n}}\}}}\{ {s(i)} \}}$

and the minimum metric may be defined as:

${MinMetric} = {\min\limits_{{i = {\{{0,1,{\ldots \; n}}\}}}\mspace{14mu}}\{ {s(i)} \}}$

The quality metric may be defines as:

QualityMetric=s(0)−MinMetric

The above mentioned 3GPP metric is defined in 3GPP TS 25.212 Appendix Aas:

${3{GPPmetric}} = \frac{{s(0)} - {MinMetric}}{{MaxMetric} - {MinMetric}}$

FIG. 5 is a flow diagram illustrating exemplary steps for processingHigh-Speed Shared Control Channels, in accordance with an embodiment ofthe invention. Referring to FIG. 5, in step 504, a plurality of HS-SCCHchannels is received. This corresponds to the maximum of 4 HS-SCCH inputbranches shown in FIG. 3 entering the Un-masking blocks 302, 312, 322and 332. In step 506, it may be determined whether the last sub-framehas been decoded successfully, whereby last sub-frame indicates asub-frame that may have been processed immediately preceding currentlyprocessed sub-frame. The conditions, which define successful decoding,are presented below with the explanation of steps 526 to 534. If thelast sub-frame has been decoded successfully, it is not necessary toprocess the plurality of HS-SCCH of a maximum of four HS-SCCH. Instead,it may suffice to process the HS-SCCH that was successfully decoded inthe last sub-frame.

If the last sub-frame was found to have been decoded unsuccessfully instep 506, the plurality of HS-SCCH first slots may be processed in block514. In step 514 comprises of Un-masking and Un-puncturing, as shown inFIG. 3. The plurality of signals is then fed into a plurality of Viterbidecoders in block 516. In step 516 corresponds to the Viterbi decodingblocks 306, 316, 326 and 336 in FIG. 3, respectively. For the pluralityof decoded data words resulting from the plurality of Viterbi decoders,the 3GPP metric and the quality metric may be computed as described forFIG. 4 in block 518, in accordance with an embodiment of the invention.In Block 520, the data word associated with the largest quality metricobtained in 518 may be selected.

Alternatively, if the last sub-frame was found to have been decodedsuccessfully in step 506, the HS-SCCH that was successfully decoded inthe last sub-frame may be processed The remaining HS-SCCH will not haveto be decoded. Hence, the first slot of the HS-SCCH that wassuccessfully decoded in the last sub-frame, is Un-masked andUn-punctured in step 508. In step 508 corresponds to the Un-masking andUn-puncturing operations shown in FIG. 3. In step 510, the resultingsignal is Viterbi decoded. This corresponds to the Viterbi decodingblock in FIG. 3. The 3GPP metric and the quality metric associated tothe decoded data word may be computed in step 512. Since, only onesignal was processed due to successful decoding in the last frame, nocomparison between different quality metrics associated with differentHS-SCCH needs to be performed.

In step 522, the 3GPP metric associated with the selected data word maybe compared to a threshold D, where D is a design parameter, asdescribed for FIG. 3. If the value of the 3GPP metric exceeds or isequal to the threshold D, the HS-SCCH from which the decoded data wordwas obtained may be assumed to have been present and the data word isoutput as the final data word. This corresponds to the output of block340 in FIG. 3. If the 3GPP metric is less than the threshold D, it maybe assumed that no HS-SCCH carrying data for the UE was present and thedata word may be rejected, as described for FIG. 3. In this case, thesub-frame decoding may be declared unsuccessful in block 532 and thedecoding process starts afresh with the next sub-frame at step 504.

In step 526, the final data word may be checked for consistencysubstantially as defined in 3GPP TS 25.214, Appendix 6A. Referring to3GPP TS 25.214, control information may be considered to be consistentif the decoded channelization-code-set information is lower than orequal to maximum number of HS-DSCH codes received in its UE capability.Notwithstanding, control information may be considered to be consistentif the decoded modulation scheme is valid in terms of its UE capability.

According to 3GPP TS 25.214, if the UE detects consistent information inthe sub-frame that is processed, it may be sufficient in the immediatelysucceeding sub-frame to decode only the HS-SCCH from which theconsistently decoded data word has been obtained. The other HS-SCCH maynot need to be decoded.

However, it may occur that the data decoded in the first slot appearsconsistent according to the definition in 3GPP TS 25.214 but containserrors. This may be possible because the error-correction capability ofthe first slot of the HS-SCCH sub-frame processed in isolation fromtimeslots 2 and timeslot 3 may be comparatively weak because the firsttimeslot needs to be processed very quickly to setup reception of theHS-PDSCH. Since all three timeslots of a sub-frame are also encodedtogether with a cyclic redundancy check (CRC) code, according to 3GPP TS25.212, Section 4.6, it may be possible to verify the data integrity ofthe first slot to a much higher degree of certitude by processing theCRC after the entire sub-frame has been received. Hence, the decisionwhether to process the plurality of HS-SCCH or only the HS-SCCHsuccessfully decoded in the last sub-frame, may be made with a muchhigher level of confidence if consistency and the CRC decode arecombined. A higher probability of correct decisions regarding theprocessing of a single HS-SCCH only provides improved data throughputperformance of the HS-PDSCH.

Therefore, in step 526, if the final word is found to be inconsistent,the data word need not be processed further and the decoding of thesub-frame may be declared unsuccessful in step 532 and the decodingprocess may start afresh in step 504. If the final data word is found tobe consistent, the final data word may be kept and waits for thetimeslots 2 and 3 of the sub-frame to be received, as shown in step 528.After all three timeslots of the sub-frame have been received, the dataintegrity of the final data word may be confirmed through the CRC decodein step 530. If the CRC confirms the integrity of the final data word,the decoding of the sub-frame may be declared successful in step 534 andthe decoding may start afresh with the next sub-frame at step 504. Ifthe CRC finds the final data word to be erroneous, the decoding of thesub-frame may be declared unsuccessful in step 532 and the decodingstarts afresh with the next sub-frame at step 504.

In accordance with an embodiment of the invention, a method and systemfor UMTS HSDPA Shared Control Channel processing may comprisecalculating at a receiver, as shown in FIG. 3, for each one of aplurality of control channels, a corresponding plurality of qualitymetrics, derived from a corresponding plurality of Viterbi Decoder statemetrics for each of said plurality of control channels. The Viterbidecoders are shown as blocks 306, 316, 326 and 336 for HS-SCCH0,HS-SCCH1, HS-SCCH2 and HS-SCCH3, respectively and the state metrics areillustrated in FIG. 4. In decision step 340, one of the plurality ofcontrol channels is selected based on the quality metrics output fromblocks 306, 316, 326 and 336 to the decision block 340. The controlchannel that will be selected may be associated with the quality metricthat provides maximum confidence in the associated decoded word.

As shown in block 522 in FIG. 5, the selected control channel isselected only if its corresponding 3GPP metric is greater than aspecified threshold D. The threshold D used in step 522 is a designparameter. The obtained final data word and the correspondingly selectedcontrol channel may be checked for validity in step 530, based on theCRC. The CRC used in step 530 may be derived from decoding all threeslots of a sub-frame, as shown in FIG. 2. The system shown in FIG. 3,processes only the first slot of the sub-frame to calculate the metricsand select the control channel. The plurality of control channels of thesystem depicted in FIG. 2, FIG. 3 and FIG. 5 comprise of High-SpeedShared Control Channels.

Another embodiment of the invention may provide a machine-readablestorage, having stored thereon, a computer program having at least onecode section executable by a machine, thereby causing the machine toperform the steps as described above for UMTS HSDPA Shared ControlChannel processing.

Accordingly, the present invention may be realized in hardware,software, or a combination of hardware and software. The presentinvention may be realized in a centralized fashion in at least onecomputer system, or in a distributed fashion where different elementsare spread across several interconnected computer systems. Any kind ofcomputer system or other apparatus adapted for carrying out the methodsdescribed herein is suited. A typical combination of hardware andsoftware may be a general-purpose computer system with a computerprogram that, when being loaded and executed, controls the computersystem such that it carries out the methods described herein.

The present invention may also be embedded in a computer programproduct, which comprises all the features enabling the implementation ofthe methods described herein, and which when loaded in a computer systemis able to carry out these methods. Computer program in the presentcontext means any expression, in any language, code or notation, of aset of instructions intended to cause a system having an informationprocessing capability to perform a particular function either directlyor after either or both of the following: a) conversion to anotherlanguage, code or notation; b) reproduction in a different materialform.

While the present invention has been described with reference to certainembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted withoutdeparting from the scope of the present invention. In addition, manymodifications may be made to adapt a particular situation or material tothe teachings of the present invention without departing from its scope.Therefore, it is intended that the present invention not be limited tothe particular embodiment disclosed, but that the present invention willinclude all embodiments falling within the scope of the appended claims.

1-24. (canceled)
 25. A method for processing signals in a communicationsystem, the method comprising: calculating at a receiver, for each oneof a plurality of control channels, a quality metric based on at leastone Viterbi Decoder state metric; and selecting one of said plurality ofcontrol channels based on a selected one of said calculated qualitymetrics.
 26. The method according to claim 25, wherein said selected oneof said calculated quality metrics provides maximum confidence that saidselected one of said plurality of control channels comprises desireddata.
 27. The method according to claim 25, wherein said selected one ofsaid plurality of control channels is chosen if its corresponding 3GPPmetric is greater than a specified threshold.
 28. The method accordingto claim 27, wherein said specified threshold is a design parameter. 29.The method according to claim 25, comprising determining a validity ofsaid selected one of said plurality of control channels based onconsistency and/or a CRC.
 30. The method according to claim 29, whereinsaid CRC is derived from decoding a sub-frame.
 31. The method accordingto claim 25, wherein said calculating and said selecting are done for afirst slot of a sub-frame.
 32. The method according to claim 25, whereinsaid plurality of control channels comprise High-Speed Shared ControlChannels.
 33. A system for processing signals in a communication system,the system comprising: one or more circuits that calculate at areceiver, for each one of a plurality of control channels, a qualitymetric based on at least one Viterbi Decoder state metric; and said oneor more circuits select one of said plurality of control channels basedon a selected one of said calculated quality metrics.
 34. The systemaccording to claim 33, wherein said selected one of said calculatedquality metrics provides maximum confidence that said selected one ofsaid plurality of control channels comprises desired data.
 35. Thesystem according to claim 33, wherein said selected one of saidplurality of control channels is chosen if its corresponding 3GPP metricis greater than a specified threshold.
 36. The system according to claim35, wherein said specified threshold is a design parameter.
 37. Thesystem according to claim 33, comprising determining a validity of saidselected one of said plurality of control channels based on consistencyand/or a CRC.
 38. The system according to claim 37, wherein said CRC isderived from decoding a sub-frame.
 39. The system according to claim 33,wherein said calculating and said selecting are done for a first slot ofa sub-frame.
 40. The system according to claim 33, wherein saidplurality of control channels comprise High-Speed Shared ControlChannels.
 41. A machine-readable storage having stored thereon, acomputer program having at least one code section for processing signalsin a communication system, the at least one code section beingexecutable by a machine for causing the machine to perform stepscomprising: calculating at a receiver, for each one of a plurality ofcontrol channels, a quality metric based on at least one Viterbi Decoderstate metric; and selecting one of said plurality of control channelsbased on a selected one of said calculated quality metrics.
 42. Themachine-readable storage according to claim 41, wherein said selectedone of said calculated quality metrics provides maximum confidence thatsaid selected one of said plurality of control channels comprisesdesired data.
 43. The machine-readable storage according to claim 41,wherein said selected one of said plurality of control channels ischosen if its corresponding 3GPP metric is greater than a specifiedthreshold.
 44. The machine-readable storage according to claim 43,wherein said specified threshold is a design parameter.
 45. Themachine-readable storage according to claim 41, wherein said at leastone code section determines a validity of said selected one of saidplurality of control channels based on consistency and/or a CRC.
 46. Themachine-readable storage according to claim 45, wherein said CRC isderived from decoding a sub-frame.
 47. The machine-readable storageaccording to claim 41, wherein said calculating and said selecting aredone for a first slot of a sub-frame.
 48. The machine-readable storageaccording to claim 41, wherein said plurality of control channelscomprise High-Speed Shared Control Channels.